Large construction structures often need to be scaled for various purposes. For example, large towers are often scaled to change or improve equipment, modify or reinforce the structure of the tower, and maintain the tower. In one particular type of tower, the cell phone tower, new innovations and increased demands have created a need to add additional weight to the cell phone tower. Often, it is necessary or desirable to reinforce the cell phone tower to accommodate the additional weight. One technique for reinforcement uses blind bolts. Typically, the blind bolt is used for reinforcing the structure with reinforcement plates mounted to the exterior of the tower or to add additional equipment to the original tower. Of course, blind bolts may be used for a variety of different purposes on a variety of different structures.
A traditional method for installing a reinforcement plate onto a tower using a blind bolt and installation tool is illustrated in FIGS. 1-3. As shown, a blind bolt 100 is mounted onto an insertion tool 102 and is inserted into a hole 104 provided in a reinforcement plate 114 and structure 106.
The blind bolt 100 includes a threaded member 116 and a number of bolt components that are placed onto the threaded member, namely a folding washer 110, a non-folding washer 136, and a nut 138. The threaded member 116 has a head 118, a shaft 120 extending away from the head. During the installation process, the head 118 of the threaded member 116 is inserted into the hole 104 in the structure 106, and is located in an inaccessible area within the structure. Some blind bolts 100 may have an expanding structure that, when positioned at the far end of the threaded member adjacent the bolt head, expands and prevents the bolt from sliding back through the hole 104. For example, in this case, the folding washer 110 is inserted through the hole 104 in a folded configuration. Once positioned on the other side of the hole 104, the folding washer 110 is unfolded and is positioned adjacent the bolt head 118. To correctly position and unfold the folding washer 110 within the structure 106, a portion of the tool 102 required to manipulate the washer is also temporarily located within the inaccessible area of the structure. Once the washer 110 is unfolded, pulling the tool 102 causes the unfolded folding washer 110 to contact an inner surface surrounding the hole 104 in the structure 106 and also to contact the bolt head 108. As a result of this contact by the folding washer 110, the bolt head will not pass back through the hole 104 in the structure 106. Thus, the far end of the threaded member 116 may be secured within the structure 106. Once the far end of the threaded member is secured, the non-folding washer 136 slides onto the threaded member and contacts an outer surface surrounding the hole 104 outside of the structure 106. Lastly, the nut 138 is secured on the threaded portion 124 adjacent the non-folding washer 136 to hold the blind bolt 100 in place in the hole. Thus, using the method discussed above, the reinforcement plate 114 may be securely mounted to the exterior of a structure 106 in order to accommodate additional weight that must be supported by the structure.
The apparatus and process described above is effective for installing a blind bolt 100 on a structure 106 in most situations. The structure shown in FIG. 3 has an internal space D1 that is sufficiently large enough to receive the threaded member 116 and a portion of the tool 102 to enable manipulation of the folding washer 110 and the correct installation of the blind bolt 100 to the structure 106. However, in certain situations, using the apparatus and process above may be difficult. For example, FIG. 4 illustrates a structure 106 having reduced internal space D2 (where D2 is smaller than D1) caused by an obstruction 112. In one example, in the case of a small-sized structure, the obstruction 112 is the wall of the structure opposite from the hole 104. In another example, the obstruction 112 may be pipes, equipment, utility lines, etc. that are located within the structure 106. In general, the obstruction 112 is anything that prevents the tool 102 from being inserted into the hole 104 sufficiently far to manipulate the threaded member 116 or the folding washer 110, as described above. Thus, the obstruction 112 can prevent the blind bolt 100 from being correctly positioned within or mounted to the structure 106.
What is needed, therefore, is an installation tool and method for installing a blind bolt into a structure having an obstruction that overcomes the issues above.